So if the rail is 2 x 84V and the amp consists of 2 full bridges, then it can be assumed that it can theoretically put out up to ~1600W into 8 Ohms per channel for very short bursts of a few ms duration. To put this in perspective, my XTI6002 (that is many times more expensive than iNuke) does clip at 144Vpk per channel into 8 Ohms, equal to 1300W bursts. The difference is that the iNuke cannot be bridged, assuming it is already 2 full bridges. And both channels into 4Ohms, the behringer can only sustain less that 1500W /ch. From my XTI6002, I have pulled 2 x 2200W (or 1 x 4500W into 8Ohms), it's PSU can suck >23Amps from the 230V supply and convert it.
Definitely not bad for the iNuke!!